I got this email, and i need to repsond to a certain adress to stand a chance of winning a great prize (that only i can win)

You have to reaply to an email address which is not given, you only receive a clue for what the adress is

Here is the clue

(2/1 + 8/4 + . + @) - 8/1 = email address

Hint: think alternative medicines...

help is apreciated